A typical forage harvester operates in a field to chop windrowed or standing crop material and includes either a self propelled or pull-type base unit with a header attached thereto for cutting or picking up crop material and feeding it rearwardly. The base unit includes a forward generally rectangular inlet opening for receiving crop material from the attachment, a feeding assembly spanning the width of the inlet opening for conveying material into the base unit, a rotating cutterhead for receiving crop material from the feeding assembly and chopping it into appropriate particle sizes. Some units employ a blower for transferring the chopped material up a spout that directs it to a vehicle for transporting it from the field to a silo or other storage apparatus, while others utilize the throwing action of the cutterhead to convey the chopped material up a spout.
One commonly known arrangement of pull-type forage harvester apparatus utilizes a transverse auger for conveying chopped material from the cutterhead to a blower. Exemplary structure of this nature is illustrated by the disclosure at FIG. 1 of U.S. Pat. No. 4,426,043, issued Jan. 17, 1984 in the name of Wayne B. Martenas. Another example of a pull-type forage harvester employing a transverse auger for conveying crop material from the cutterhead to a blower is disclosed in U.S. Pat. No. 4,505,434, issued Mar. 19, 1985 in the name of Wayne B. Martenas, et al.
Insofar as self propelled units are concerned, it is not uncommon to convey chopped material along a direct path between the cutterhead and an inlet to the blower, i.e., no intermediate conveying means are employed. U.S. Pat. No. 5,103,622, issued Apr. 12, 1992 in the name of Larry D. Hall, et al, shows a forage harvester that is representative of prior art self propelled harvesting units without intermediate conveying means.
Regardless of whether a pull-type or self propelled unit is being considered, it is necessary to accommodate a variety of crops, corn being one of the more common types. While chopping corn with a forage harvester, it is not uncommon for less than half the kernels to be cut or cracked by the cylindrical cutterhead. Due to peculiarities of the digestive system of cattle, the full food value of the feed is not utilized in circumstances where the kernels are uncracked or uncut, regardless of the reason. Accordingly, prior art forage harvesters have been provided with crop processor assemblies for further cracking and cutting of the kernels to overcome this problem and enhance the nutritional characteristics of the resulting harvester output.
It is known in crop processor structure, to mount paired crushing rolls in the path between the cutterhead and blower of self propelled forage harvester apparatus. An example of structure of this nature is disclosed in U.S. Pat. No. 5,527,218, issued Jun. 18, 1996 in the name of Bart Van den Bossche, et al. Similar structure is shown in U.S. Pat. No. 4,678,129, issued Jul. 7, 1987 in the name of James F. Dallinger. In both the aforementioned patents, the crop processor structure, located below the cutterhead, feeds processed crop material to a blower having an inlet located below the processor. This general arrangement of cutterhead, processor, and blower inlet is also disclosed in U.S. Pat. No. 4,345,417, issued Aug. 24, 1982 in the name of Harold E. deBuhr, et al. In this patent an auger assembly is disposed rearwardly and below the processor rolls for receiving crushed crop material and conveying it to the blower inlet. In other prior art forage harvesters, processors have been mounted between the cutterhead and the discharge spout, e.g., see German Patent No. DE 33 37 381 A1, issued Apr. 25, 1985 in the name of Claas oGH.
Crop processors are also incorporated in pull-type forage harvesters, an example of which is a unit manufactured and sold by New Holland North America, Inc., assignee of the present application, under the Model Number 900, shown in a brochure published under No. 33090010-89820-VPC. U.S. Pat. No. 5,822,962, issued Oct. 20, 1998 in the name of Robert A. Wagstaff, et al, is a similar showing of a pull-type forage harvester with crop processing capability. Another pull type harvester shown in U.S. Pat. No. 4,718,612, issued Jan. 12, 1988 in the name of Petrus W. Zweegers shows a processor operative between the cutterhead and the discharge spout. This type of unit is sometimes referred to as a cut and throw forage harvester.
Regardless of the overall structure involved, during operation, the flow of crop material in forage harvesters is not uniform and the ensuing flow across the width of a processing roll is uneven, leading to localized excessive wear, resulting in reduced cracking effect of the corn kernels at the worn area. Eventually, a new processing roll or a new pair of rolls must be installed to assure proper processing of the kernels. The roll is a highly tooled costly element. To reduce the cost involved in repairing or replacing the roll, European Patent Application No. 0664077, published Jul. 26, 1995in the name of New Holland Belgium N.V., shows a roll with replaceable end sections, both of which are situated in the portions of the processor in this particular harvester subject to the occurrence of significant wear problems. These two relatively narrow sections are attached in coaxial fashion to the ends of a relatively wide central section, thus avoiding the need for replacing the entire costly roll assembly.
Unique characteristics of the present invention, described below, contribute to a processor roll for a forage harvester with reduced costs involved in repair and replacement due to excessive wear and damage that, among other things, enhances performance, serviceability and durability.